1. Field of the Invention
This invention relates to a process for producing ferrous picrate and a fuel additive containing ferrous picrate.
2. Description of the Related Art
As stated in U.S. Pat. No. 5,087,268 of Walter W. Parish, numerous patents have been granted for processes which utilize picric acid, some form of iron, and a solvent to produce an additive for hydrocarbon fuels which increases the efficiency of the combustion of such fuels, resulting in better mileage, reduced deposits within the engine, and a smaller quantity of pollutants in the exhaust.
In the context of the present invention, U.S. Pat. No. 5,087,268 is, in fact, the most significant patent of the prior art.
The disclosure in U.S. Pat. No. 5,087,268 observes that stability is enhanced because the process of that patent does not require the use of water; however, U.S. Pat. No. 5,087,268 does not otherwise explicitly consider controlling the concentration of water which is present in the reaction mixture. And not only is water always introduced with picric acid since picric acid is universally contained within water for shipment because dry picric acid is explosive; but all of the activating acids used in the process of U.S. Pat. No. 5,087,268 to remove any substances from the surface of the iron to expose a surface of pure iron are solutions of the activating acid in water and, therefore, introduce water when included within the reaction mixture.
Furthermore, the present inventor has learned that difficulties are generated for the fuel additive by too little water, as well as by too much water. A concentration of water which is too high causes the ferrous picrate and the fuel additive to degrade over a relatively short period of time; and a concentration of water which is too low substantially increases the time required to produce the ferrous picrate and the fuel additive.
A similar situation exists, moreover, with respect to nitrates and sulfates. U.S. Pat. No. 5,087,268 correctly observed that not requiring sulfates in its process enhanced the stability of the ferrous picrate fuel additive. Again, however, other than not using sulfates in its process, U.S. Pat. No. 5,087,268 did not explicitly provide any technique for controlling the presence of sulfates and did not even mention nitrates, which also have a negative effect upon the stability of the fuel additive, except for the comment that nitric acid caused instability in the additive.
Finally, U.S. Pat. No. 5,087,268 simply refers to agitation of powdered elemental iron. But the inventor of the present process has discovered that the reaction of picric acid with the iron metal is a surface phenomenon. Therefore, because a molecule of picric acid is very large in comparison to an atom of iron (The molecular volume of picric acid is 129.95; the molecular volume of iron, 7.11.), once an atom of iron has combined with two molecules of picric acid, a molecule of ferrous picrate, which is even larger than the picric acid molecule, exists on the surface of the collection of iron atoms and, by its shear size precludes other molecules of picric acid from reacting with iron atoms that are in the vicinity of the one iron atom which has already reacted. Furthermore, ferrous picrate is ionic and, thus, a polar molecule exhibiting magnetic properties. Since an atom of iron is magnetic, a polar ferrous picrate molecule will be magnetically attracted to iron atoms. Consequently, mere agitation does not create adequate force to move the ferrous picrate molecules away from the unreacted iron molecules; to achieve a reasonable reaction rate, a ball mill must be employed.